A busy start to 2025
We are well into summer, and the Island is alive with many visitors from around the globe.
The newly-fledged birds are familiarising themselves with their beautiful island home and mingling with all those fortunate enough to be ferry passengers to this island gem. Many volunteers and staff make possible the continuing success of Tiritiri Matangi in various ways, bringing their talents to assist in delivering the plans and vision for this conservation project. Those who have enjoyed a guided walk consistently commend you on your work, and your efforts are widely acknowledged. Thank you!
As indicated at the last AGM, changes will progressively be made to the governance structure. The main committee is now referred to as the Board. Of importance to members is the existence of proper governance of their incorporated society to ensure leadership, stewardship of the assets, decisionmaking, and guardianship of the precious flora and fauna.
In line with that, steps to fill Board vacancies are underway, and two new members who were co-opted at the last board meeting are introduced below.
At our first meeting in February, the Board will start the important process of reviewing future plans. The 10-year strategic plan is due to expire in 2027.
The major project in 2025 will be to commence physical works on the field centre, possibly around mid-June.
I look forward to meeting more of you on the Island soon.
Ian Alexander
Kia ora tātou.
Island News
Wild Working Weekend
A lightning strike near the bunkhouse woke its occupants at 3 a.m. on Sunday, but despite the sometimes wild weather, a team of hard-working volunteers completed plenty of work over the holiday weekend.
My name is Meredith Blogg and I’m thrilled to join the team in my new role on the SoTM Board.
I visited the motu for the first time shortly after arriving from Canada in 2022. I was instantly enamoured and wanted to find a way to contribute my time and energy to this taonga.
I signed up for working weekends and I haven’t looked back since!
I’m an enthusiastic primary school teacher at Ardmore School and the Enviro Kaiako for my kura as well. I am passionate about inspiring rangatahi in their kaitiaki mahi. I had the honour of bringing 50 of my ākonga over to the motu last year and am excited to offer this experience to new students this year. I look forward to growing my knowledge and expertise with SoTM in the year ahead!
My name is Mark Withers. I recently retired from a 30-year career as a chartered accountant at the firm I founded, PKF Withers Tsang.
Living on the Gulf Harbour waterway, I have developed a deep affection for Tiritiri Matangi and its unique flora and fauna. I am eager to contribute to the association that preserves and protects this special place.
During my career, I have held governance roles for several incorporated societies. I was treasurer and am a life member of the Auckland Property Investors Association. I have also been treasurer of the Lake Tarawera Ratepayers Association Inc. and the Rangitane Recreation Association Inc.
With my accounting and governance skills, I am eager to contribute to the association. This is an opportunity to give back to the island I love and join a team that shares my passion. I look forward to working with the Board to deliver excellent outcomes for the users of Tiritiri Matangi.
For translating Te Reo words to English see https://www.maoridictionary.co.nz/
Cover photo: A tūī chick begs for food, Tony Petricevich
Donna Miller, Carolina Merino and Lukas González; eager volunteers, ready for work
Sam Gill and Milly Keymer paint new boards to replace the old, rotting ones at Hobbs Beach
Photo: Meredith Blogg
Photo: Meredith Blogg
A family affair - Introducing Tiritiri's new DOC ranger
Before starting his role on 31 January, the Island's new ranger, Nick Fisentzidis, shared a little about himself and his family with Dawn Chorus.
Please would you tell us about your career?
After finishing my geography degree at Victoria Uni, I started in the DOC national office in 2007 and had several roles in the Department until starting full-time island life in 2012. My partner, Genevieve, and I have been based on islands since 2012, starting with Kapiti (2012-2018), Mana (2018-2021), and most recently Te Pākeka / Maud Island (2021-2025).
Please would you tell us a little about your family?
For our first four years on Kapiti, before our son Theo was born, Gen was the island ranger, and I was the hihi contractor. We then job-shared both the Mana and Te Pākeka island ranger roles and have also completed project work for the Department’s veterinarian from time to time. Theo (8) wants to be an electrician when he grows up, and our daughter Georgia (5 1/2) wants to be a vet – ask again in five minutes for a different answer…
It’s been a while since children lived on the Island. What is the family most looking forward to about the move?
More birds, tuatara, whale watching, snorkelling in warmer water, and the lighthouse!
Will the children be homeschooled through Te Kura (NZ correspondence school)?
Yes, both our kids are homeschooled and have been enrolled with Te Kura since pre-school.
What hobbies/interests do you have?
I’m a lapsed tramper and player of sports – both hard hobbies to keep up being island-based. Thankfully, I’m starting to rekindle these pastimes as the kids get older.
Chinese delegation visit Tiritiri
officials responsible for a majority of
Island on 14 December 2024. Following their guided walk, the visitors and Supporters of Tiritiri Matangi exchanged gifts.
What areas of conservation most interest or concern you?
I’ve mainly had biodiversity-focused roles (hihi, takahē) while working in conservation, but I enjoy the varied nature of island positions.
Finding suitable mainland sites for threatened species is a nice problem to have, thanks to the success of predator-free islands.
Is there anything more that you would like to add?
The family and I are excited to see a different type of island life than we have been used to – one where a lot more of the public can visit and experience what we feel lucky to experience every day.
Repairs to The Landing's ramp
The storms of the summer before last caused significant damage to the ramp used for offloading heavy equipment and supplies delivered to the Island.
DOC contractors have now repaired the ramp. It was a massive undertaking involving digging a large hole for underpinning and replacing a section of the concrete ramp.
Nick, Theo, Genevieve, and Georgia as they depart Te Pākeka / Maud Island
Photo: Nick Fisentzidis
Seven
the conservation estate in China visited the
Photo: Taken by a member of the delegation
Photos: Neil Davies
The Landing's ramp, essential for offloading equipment, before and after repairs
Photo: Janet Petricevich
The barge transporting machinery
Zhiming Hao presenting a gift to SoTM. Accepted by Gail Reichert and Ian Alexander
New vehicles for Tiritiri Matangi
DOC and SoTM have expanded the Island's transportation fleet. Suitably trained volunteers now have more options for getting around the motu.
SoTM has purchased a second LUV, as our first Viking is probably nearing the end of its useful life. The new vehicle has been named Ray in honour of Ray Walter. DOC has purchased two electric bikes to provide more environmentally friendly transportation options. One is a cargo bike, while the other is a regular-style bicycle.
and
Tiritiri Matangi 2025 Photographic Competition
We're now looking for entries for our photographic competition (and photos for our 2026 Calendar). The categories are:
• Fauna
• Landscape/Seascape
• Under 16 years old
• Flora
• People on Tiritiri Matangi
All photos must have been taken on Tiritiri Matangi Island. Landscapes of the Island may also be photographed from boats. You retain image copyright and can enter up to four photos in each category. Entries close April 30, 2025
Details and image use policy are at: www.tiritirimatangi.org.nz/news
Vikings, 'Eric' and 'Ray',
E-bikes, 'Mo' and the Haibike
Simon Fordham using 'Mo' to deliver new rifleman nest boxes prior to the start of the breeding season
Photos: Janet Petricevich
Photo: Geoff Beals
Photo: Martin Sanders
Guest Guide
When one of our editors was staying in the bunkhouse recently, a group of overseas visitors told her how wonderful their guided walk had been. They said that their guide had been amazing. He was knowledgeable and extremely passionate about Tiritiri and conservation. She asked them the name of the guide who had such an impact during their first hours on the Island. The guide's name was Neal Taylor, and he is this issue's guest guide.
Where were you born / where did you grow up?
I was born in Gisborne and grew up in Auckland. My grandparents were the first honorary rangers for Le Roys Bush on Auckland’s North Shore in the early 1900s and my grandmother would take me into the bush when I was very young and talk to me about the plants, the birds, and koura / freshwater crayfish in the streams.
I would look out at Tiritiri in the days when it was farmed as I walked home from Rangitoto College. At home, my father would point out the barges that carried sheep and cattle from the Island to Auckland and tell me about them and the history they represented.
How did you get involved with Tiritiri Matangi?
Around ten years ago I was volunteering on a conservation project, and we had a fund-raising pop-up shop in Browns Bay. It was a hot and lazy Friday afternoon, and the sales activity was minimal. For something to do, I asked my covolunteer what she was doing at the weekend. She told me she was going to Tiritiri as a guide. Well, that’s all I needed. The rest is history, as we say.
How has guiding changed from when you started?
I think we are more structured as a team now, which I see as necessary given the number of visitors we receive on the Island. It enables us to be focused on the guiding task. It’s pleasant, too, to build friendships with other guides on the Island the same day as I am.
What has been your favourite experience with guiding?
My favourite experience is an ongoing one. I value the opportunity of guiding schoolchildren. In many of my school groups, there is a small number of children who ask searching questions or make enquiring comments about the environment they are experiencing on the day. When I get a suitable opportunity, I ask them why they asked a particular question or what prompted them to comment. Mostly I know their answer before I ask. And what is the answer? It’s something like ‘Oh my parents take me/us for a walk in the bush or the park or shoreline to see what nature has for us’. This has a wider message for all of us, I think.
What tips would you give someone starting to guide today?
This is very easy to answer. I learned it early in my guiding life. It’s two things. One is to not give the visitors in your group too much information while walking. Learn to ‘read’ your group and structure your presentation as you think is appropriate. The other is to talk from your heart about the Island’s natural environment and relate it back to our wonderful planet. This can generate a real interest in our visitors’ understanding of the need to control introduced plants and animals in New Zealand and the need to protect our planet. Recently this prompted a lovely lady in my group to say, ‘Oh I’m the chairperson of Predator Free Herne Bay’. Music to my ears!
What is your favourite story about Tiritiri Matangi that you like to share with visitors?
I tell the visitors about the lighthouse in the 1960s when at night the light would fill my parents' lounge in Mairangi Bay and the foghorn would sound with a low moaning sound when there was low cloud and fog out in the Gulf. Even though this is a simple story it gives the visitors some idea of the history of the Island and the functionality of the lighthouse area.
What is your favourite bird on the Island, and why?
I love them all. I delight in seeing the toutouwai / North Island robin. When they come close to check out my group, I talk to them. They seem to look at me and understand everything I say to them.
What is your most memorable experience on the Island?
I know this may sound rather simplistic, but my most memorable experience is one that happens quite frequently. I always carry a magnifying glass with me. I feel undressed if I don’t have it with me. I stop where there are plenty of māhoe leaf skeletons and get the visitors to look at the leaf skeleton through the magnifying glass. The visitors are absorbed by what they see and there are two responses. From the children it is ‘Cool’ and from the adult visitors, the response is ‘Wow’, every time. I tell them it’s a gift from Papatūānuku (Earth Mother) and sadly many people will never get to see such riches from nature.
Is there anything else you would like to share?
If there is any message that I can offer it is simply that our Island is an example of what and how our natural NZ environment used to be before humans modified it, when we settled on the land. It’s a good time to remind all visitors, especially New Zealanders, of our obligation and duty to help Papatūānuku (Earth Mother) and Ranginui (Sky Father) care for our planet. Predator Free NZ is a good place to start.
Photo: Linda Taylor
Neal on the island that he is passionate about, Tiritiri Matangi
Karo - a frontline species for coastal protection
A plant that had an outstanding flowering season on Tiritiri Matangi Island during the spring of 2024 was Pittosporum crassifolium, better known by its Māori name, karo.
As this issue of Dawn Chorus goes to print, the results of this flowering are obvious: big grey seed pods (capsules) are hanging in abundance on karo branches all over the Island.
The pods are attractive. They bob in the wind in tandem with the plant’s leaves, which flicker between the green upper and grey undersides, creating patterns and hues in constant change. Have you noticed their profusion this year?
Island presence
Botanist Alan Esler recorded the first surveyed wild population of Pittosporum crassifolium on Tiritiri Matangi Island in the early 1970s.
Before this, rats were present, and animals had grazed the Island for around a century, limiting the survival of many plant species, including karo.
Between 1984 and 1994, copious quantities were planted during the Island’s revegetation programme.
Now they regenerate freely in suitable habitats and can readily be seen lining the coastal edges of the track to Hobbs
Beach, often in a front-line position, intermingling with harakeke/flax (Phormium tenax), taupata (Coprosma repens), muehlenbeckia and pōhutukawa (Metrosideros excelsa) amongst the boulders on the beach fringes.
They also thrive on forest margins, cliffs, and rocky outcrops all over the Island, where larger trees have not stolen their light, and the soil is relatively well-drained.
Distribution
Pittosporum crassifolium grows elsewhere in areas with habitats similar to those of the Tiritiri Matangi population. Its natural range extends from North Cape to Poverty Bay and on many northern offshore islands.
They have also naturalised in other warm areas of New Zealand, Norfolk Island, and the Hawaiian Islands, where they may be considered a weed species.
There are around 250 species of Pittosporum worldwide, twenty-one of which, including karo, are endemic to New Zealand. All belong to the evergreen Pittosporacea family.
Top left: A female flower with one prominent central pistil. Bottom left: A male flower with pollen-bearing stamens. Right: A kākāriki eating karo flowers
Photos: Jonathan Mower
Growth habit and description
Karo are fast-growing colonisers, able to inhabit coastal positions that few other plants can tolerate. Consequently, they contribute to the overall stability of coastal ecosystems, helping with erosion control and providing shelter for the next layer of vegetation to grow behind.
Within ten years and in ideal growing conditions, they will form into a dense shrub or an erect, multi-branched small tree up to ten metres tall and three metres wide.
Their alternating, thick, leathery, oval leaves (5-7 cm long) curve inwards at the margins, reducing surface exposure to the dehydrating salt-laden winds of their coastal habitat.
They are also covered underneath in downy, grey, felt-like hairs (tomentose) that help prevent salt penetration to the leaf’s surface, another clever survival technique. Tomentose also occurs on the soft new-season growth that readily shoots from branch tips.
Bird food—the flowers
In spring, small dark crimson flowers appear in terminal clusters. Their sweet perfume fills the evening air, attracting bees, flies and nocturnal moths to aid pollination.
However, by day, nectar-feeding birds such as korimako/ bellbirds, hihi/stitchbirds, tūī, kererū / New Zealnd pigeon, and kākā are lured in to help with pollination – receiving in exchange their fill of sweet sugary syrup from the flowers. Korimako are particularly well-designed for the job.
Close inspection of the pretty flowers will reveal that male and female flowers are on separate plants, the males in larger bunches than the females.
The females have one prominent central pistil (stigma and style atop an ovary). In contrast, the males have an often sterile, small central pistil surrounded by five yellow pollenbearing stamens (filaments and anthers). In other words, the male flowers are hermaphroditic, or ‘inconstant' in botanical terms.
When the inconstant male flowers self-pollinate, the resulting seed pods are smaller, and the seed is less viable than those born on karo's female-flowered trees. Have a look and see if you can notice the difference.
The process of having one flower ‘inconstant’ and the other ‘constant’ (pure) on separate trees is known as gynodioecy. This rare phenomenon is thought to be an evolutionary bridge between hermaphroditism and dioecy (separate male and female plants).
Bird food—the
fruit
Compared to its small flowers, karo’s round, 2-3 cm long, three-part seed pods are a significant sight. The male-set pods often hang sparsely and singly, while the female fruit hang in clusters of up to ten. However, most frequently, I’ve observed clusters of two to six.
These pods are also covered in protective tomentose, giving them their soft grey/green colour. During autumn and winter, the pods mature and burst open, revealing a mass of black seeds in a sticky yellow substance known as gluten.
Consequently, seed dispersal beyond the tree’s dripline is difficult without external assistance, so seedeaters like tūī, kererū, kākā, kōkako, and kākāriki help with the process.
In return for a meal, they inadvertently fly off with the sticky seed attached to their bodies, distributing it—along with the undigested seed—further afield.
Pods can hang onto the tree for up to six months, turning hard and black as they dry out. Maybe you have noticed them. Enjoy taking a closer look at these important coastal frontliners.
Natalie Spyksma
Karo seed pods
Photo:
Annette de Raat
Photo: Natalie Spyksma
Karo seed pod open showing the sticky karo seeds
A bumper breeding season
Hihi/stitchbird
It has been busy in the hihi world, with 82 females attempting to breed this year. Usually, we get 60-70 females breeding, but they pulled out all the stops this year. With the flax flowering and the mild weather, it's been a good year for hihi.
The 200 th chick was banded on January 10 th, and more banding will follow during the rest of January. About 40 females have attempted second nests this year, but the season appears to be winding down, and it doesn't look like there are third clutches on the horizon.
Over 150 fledglings are out and about in the big wide world of Tiritiri Matangi. If you think you see lots of female hihi on the Island, think again. Some of them are probably fledglings. They look like females, but the fledglings will have smart feathers, might have a bit of a yellow gape by their mouth, and will be very curious. All our fledglings this year will also have three colour bands and a metal band. So, keep your eyes peeled.
Takahē
Anatori and Wakapatu have one chick, and the family is regularly seen in the lighthouse area.
Atawhenua and Turutu, who live at the Island's northern end, have nested but have not produced any chicks this season.
Kākāriki
The kākāriki season starts later than most birds, with eggs typically laid in November. This year, we have ten pairs in the nest boxes, slightly fewer than average.
By early January, 45 chicks had hatched, and 43 were still alive. We don’t know all the clutch sizes as we try to avoid flushing the incubating females, but there were a couple of eight-egg nests and none had less than four.
Not all the remaining chicks will survive to fledge. The average chick survival rate for the last eleven years is 52%, but it has varied from zero to over 90%.
The large plastic nestboxes seem popular with other species. So far
this season, we’ve found eleven with wētāpunga, three with Duvaucel’s geckos, four with titipounamu nests, one tīeke/saddleback nest, and one myna nest.
Titipounamu/rifleman
Once again, riflemen abound on the Island, with many visitors and guides reporting multiple encounters. Since early December, over 200 individuals have been caught, around half of those being this season’s juveniles. Pairs attempted to nest at 29 riflemen nest box sites, and, as usual, a similar number used nest boxes of other species (hihi, tīeke, and kākāriki). For the second consecutive year, one pair nested underneath the bunkhouse bathroom.
The 200 th hihi chick banded on Tiritiri this season
Kākāriki chicks in a nest box
Anatori and Wakapatu's chick
Photo: John Sibley
Photo: Emma Gray
Photo: Tony Petricevich
Kōkako
There are now 26 confirmed pairs, with a possible 27th pair.
As of now (late January), we have four pairs incubating, including two pairs that have already successfully fledged a chick. Six pairs are feeding nestlings, including two pairs that already have a fledgling from a previous nest. There are thirteen fledglings. Seven pairs have one fledgling, and the other three have two fledglings. This includes Waitangi and Lyric, who have successfully fledged chicks for the first time.
Some pairs are on their third nesting attempt after previously failing. Six pairs are in between nesting attempts.
Several of last season’s youngsters without territories have been seen in the territories of established pairs. This has led to a lot of extra singing, followed by pairs chasing the offenders out of their territories.
Other birds
Kororā / little penguin
It’s great to report on a much more successful nesting season for our kororā after all the first-clutch chicks died last year. We eventually had twelve pairs occupying nest boxes: eleven laid two eggs, all but one hatched, and all 21 chicks fledged.
Later in the season, four pairs attempted second clutches. By the 11th of January, two of them were still going well, with two chicks each. This is a remarkable turn-around and indicates that there have been sufficient food resources over the whole nesting period this season.
Unusual sightings
Tiritiri Matangi never fails to produce amazing encounters for all the volunteers, but on November 3rd, it was the turn of the shop and office volunteers to be wowed.
‘Before the shop opened, we heard a bird strike the glass ranch slider and fall on the mat outside. It was a bird we seldom see on the Island — a koekoeā / Pacific long-tailed cuckoo. It was still alive! So, we barricaded off the outside entranceway, stationed a guard to ensure it got space, and left it alone to recover. A few of us could photograph it from inside the shop. Because the bird was hunkered down and splayed out, you could see details of its plumage. Our encounter was over in about 15 minutes as the bird recovered and departed, flying strongly down the grassy hill towards the bunkhouse.’
Long-tailed cuckoos return to New Zealand in early October from their winter home in the Pacific Islands (mainly east of Fiji) to breed, always returning to the same site year after year. They lay their eggs mainly in the nest of pōpokotea/whiteheads, so it's not surprising that they come to Tiritiri.
Compiled by Kathryn Jones, with contributions from Emma Gray, Morag Fordham, Simon Fordham, John Stewart, and Yvonne Vaneveld
The first kōkako chick to fledge this season (Shelly and Tama)
A koekoeā / Pacific long-tailed cuckoo on the ground outside the Island shop
An adult penguin with their chick
Photo: John Stewart
Photo: Yvonne Vaneveld
Photo: Alison Forbes
Juvenile female titipounamu banded Christmas Day (RG-YM)
Photo: Tony Petricevich
How biodiversity richness in a community can bring stability and survival advantages
A balanced seagrass community is generally harmonious – but not always!
The November issue of Dawn Chorus presented a picture of our seagrass, Zostera muelleri, as an important keystone species. The seagrass meadows off Tiritiri support an impressive array of animal and plant species that can live there because the seagrass modifies their physical and chemical environment. One hundred and thirty-one species have currently been identified inhabiting the seagrass meadows between Hobbs Beach and the wharf.
In this issue, we are taking a closer look at some organisms living amongst the seagrass. Most benefit a healthy community, but one or two can be harmful if the environment is disturbed. There are also opportunistic species that are mostly harmless but can occasionally get out of hand, primarily due to human influences. Surprisingly, in a balanced community, even the presence of harmful species is usually not disastrous.
Two exotic warm-water species, Caulerpa brachypus and C. parvifolia, have recently invaded parts of the Hauraki Gulf. They are growing rapidly, smothering scallop and pipi beds, causing severe ecological and economic damage to the marine environment. Yet, in its usual habitat off the east coast of Australia, Caulerpa is a well-behaved member of the inshore seabed ecosystem. Off Sydney, the seabed community contains many other species of algae that compete with C. brachypus and C. parvifolia for nutrients, light, and space. In addition, various resident invertebrates and fishes nibble and trim the Caulerpa, keeping it under control there. These are absent from our waters, and the Caulerpa grows unchecked.
The impact of human activities is evident in the Hauraki Gulf. These include sediment runoff, nutrient pollution from treated sewage, overfishing, and global climate change. Our seagrass community needs great resilience to survive the environmental disturbances wrought by human activities.
Above all, Zostera muelleri requires good light to thrive. For this reason, it grows best in shallow water at low tide levels. Light levels fall rapidly in deeper water, and its growth is much weaker. Other factors that reduce light intensity will have a similarly negative effect on its development and health. For example, suspended sediment blocks light and enters the Gulf mostly from river and stormwater runoff. As Auckland grows, ever-increasing construction work in the region generates sediment runoff. The nutrients in discharged sewage add to the problem by boosting algae growth, including opportunistic epiphytic species that attach themselves to seagrass leaves. Epiphytes like Ectocarpus, Ceramium, and Melobesia use the seagrass leaves as anchoring platforms to gather as much light as possible for themselves at the expense of the seagrass beneath.
A mixed-algae balanced community including Caulerpa brachypus off Sydney
Epiphytic algae growing on a clear plastic 'leaf'
Left to right: Deeper water means less light and weaker plants. Epiphytic Ectocarpus algae and assorted diatoms block light too
Steve Smith, (Atlas of living Australia).
To measure the amount of light blocked by these epiphytic algae, several artificial transparent PVC seagrass ‘leaves’ were anchored amongst the Hobbs Beach seagrass beds and collected seven weeks later for analysis. This revealed an unexpected twist to the story. It was found that the plastic surfaces did not grow the same combination of epiphytic algae species that real leaves did. At least one completely different alga species called Ralfsia was found on the artificial leaves, and other species common on real leaves were absent on the plastic ones. Melobesia was not affected either way and grew well on both surfaces. The reason for this difference in substrate preference is not apparent, but some algae appear to be getting more than just physical support from the real seagrass leaves. Perhaps certain substances diffuse out of the living seagrass leaves, accounting for this difference.
A harmful single-celled organism called Labyrinthula zosterae in the seagrass community causes seagrass dieback disease. This pathogen caused the mass death of extensive seagrass meadows off northern hemisphere coasts in the 1930s. It is a strange microbe that was classified initially as a fungus, then as a slime mould — but has now been re-assigned to an unusual phylum, the Bigyra (Latin for ‘twice circle’), a reference to how it moves. It uses a clever strategy that allows it to kill large areas of seagrass rapidly. Its cells exude slime trails, forming an ectoplasmic net or labyrinth around the seagrass blades. Instead of progressing by steadily infecting cells one at a time, they use this external slime labyrinth to move efficiently across the surface of the seagrass leaves, rapidly infecting cells as they go, leaving blackened dead regions in their wake. Once a quarter of the cells of a leaf are infected, the fate of the rest of the leaf is sealed [1]. Photosynthesis drops to net zero, and death soon follows. Labyrinthula is a cosmopolitan species thought to be present to some extent in all seagrass beds. Damaging outbreaks often occur when plants are stressed by adverse environmental conditions, which may weaken the plants, allowing the disease to do severe damage. On Tiritiri Matangi, infected seagrass areas often appear as dark patches. Fortunately, recent infections have been limited to no more than a few isolated sections of seagrass. Extreme weather events like storms can inflict severe physical damage, making plants more susceptible to infection. Other known stressors often preceding Labyrinthula attacks are trampling, sediment/epiphyte shading, sewage pollution, and marine heat waves.
Okeania is a photosynthetic cyanobacterium that normally lives inconspicuously amongst the seagrass. It can increase to harmful levels when excessive nutrients are available. Representing one of the earliest life forms on Earth, the cyanobacteria appeared some 3.5 billion years ago, so it has had plenty of time to develop strategies for competing successfully in a crowded environment. They have an extremely rapid growth rate, multiplying from very low numbers to plague proportions within days. Their slime-coated strings of cells can glide and move over each other to form a tight-knit, smothering blanket covering the seagrass plants. Potent toxins are produced to deter grazers and inhibit the growth of potential competitors. Bathers who swim over the affected seagrass can develop rashes and contact dermatitis.
A large proportion of the animals inhabiting the seagrass beds are herbivores or scavengers who help keep the seagrass leaves relatively free of algae and detritus. From tiny ‘Rissoid’ snails with sandpaper-like tongues to dainty emerald-green shrimp delicately picking morsels from the surface of the leaves, these form the beneficial ‘maintenance crew’ of the seagrass community.
Labyrinthula zosterae – Seagrass wasting disease has infected this runner
Slime trails form the ectoplasmic net or labyrinth acting like a highway enabling the microbes to spread rapidly
Okeania covers seagrass in a sticky black toxic layer. Oxygen bubbles are produced, which raise parts up like dark slimy fingers
Maple Ferryman.
The cleanup team. Snails and crustaceans help to remove epiphytic algae and diatoms
Labyrinthula microbes advancing across an infected leaf
Five species of New Zealand marine caddisflies are found off our shores. Their larvae graze on diatoms and larger algae attached to seagrass leaves. Starting life inside cushion starfish and feeding on their soft tissues, they soon emerge and change their diets to become strict vegetarians consuming algae. These five species are the only genuinely marine insects in the world.
Seagrasses are also noteworthy as they are the only flowering plants (Angiosperms) living their entire lives submerged in seawater. This presents a problem for pollination. Land-based flowering plants fertilise their ovules with dry pollen carried by the wind or with the help of animals like bees. Marine seagrass flowers exude a sticky pollen paste that some marine crustaceans and caddisfly larvae eat. As they do so, they transfer some of the sticky pollen to other plants, fertilising the seagrass flowers and earning them the name ‘sea bees’.
This year, the total area covered by the seagrass meadows has steadily increased. Satellite data can be used to monitor the growth rate, and Google Earth has added an area measurement tool and access to previous years' historical photographs. The latest area measurements give a combined total of 1.5 hectares (approx. 3.7 acres). This includes the deeper beds out towards the rocky outer reef. Year on year, the growth rate is linear, with an annual increase of about 16%. If this continues, the area covered will roughly double every six years.
The influence of the seagrass on the dynamics of the seabed in the bay is evident. As the seagrass absorbs the energy of incoming waves, sand drops out of suspension. In this way, sand levels across the bay have risen, even in areas not colonised by the seagrass, and a prominent sand bar has appeared extending across the bay parallel to the beach. More exposed sand at low tide now attracts feeding tōrea pango / variable oystercatchers. Matuku moana / white-faced herons sometimes catch jack mackerel stranded in pools of seawater retained by the more extensive seagrass beds at low tide.
The rapid increase in biodiversity will surely attract other shorebirds as time passes. When you walk along Hobbs Beach at low tide, please watch for new shorebird sightings so we can update our records!
John Sibley
Reference:
[1] Peter J Ralph, Frederick T Short. Impact of the wasting disease pathogen Labyrinthula zosterae, on the photobiology of eelgrass Zostera marina Marine Ecology Progress Series. 2002, Volume 226: P265-271
All photos author's own, unless otherwise noted
A tidal pool created by an expanding seagrass bed provides feeding opportunities for white-faced herons
Tiritiri’s seagrass beds at low tide. A new sand bar has formed as the seagrass causes sand to drop out of suspension
Isopod crustaceans can also cross-pollinate Zostera flowers
Marine caddisfly larvae graze on algae and diatoms
Honouring Ray Walter: A tribute to New Zealand's last lighthouse keeper
On Saturday, 30 November, Supporters of Tiritiri Matangi (SoTM) hosted a Lighthouse Open Day to honour the life and work of Ray Walter, who sadly passed away in October 2023. Ray was the last lighthouse keeper on the Tiritiri Matangi station and, when the lighthouse was automated in 1984, he stayed and led the planting programme along with Barbara Walter. This special day was a tribute to Ray’s 27 years of service to the lighthouses of New Zealand.
The Tiritiri lighthouse, built in 1864, is New Zealand's thirdoldest lighthouse and the oldest operational one. It has guided, and continues to guide, countless ships safely through the Hauraki Gulf, playing a crucial role in maritime navigation.
Guided by personnel from Maritime NZ (the owners of the lighthouse) and SoTM volunteers, visitors had the unique opportunity to climb to the top of the lighthouse, where they were treated to breathtaking panoramic views. Even though it was overcast, the views were still impressive. From this vantage point, they could see for miles, taking in the stunning landscapes of the Hauraki Gulf and beyond. Jim Foye, Rob Gouldstone, Carl Hayson, and Ian Higgins guided 120 people through the lighthouse. Gaye Hayson and Cathy Catto were at the bottom of the tower, organising and briefing the visitors before they entered.
Ray Walter's legacy was celebrated with his wife, Barbara, and some of his family, including daughter Lynda and son Mark. Displays were set up in the Visitor Centre outlining the many lighthouse stations Ray served on, and pictures showing Ray in his younger years (minus facial hair) were fascinating. His tireless work laid the foundation for the thriving sanctuary that Tiritiri Matangi is today, and his continued strong interest in New Zealand lighthouse history has formed the basis of the maritime restoration work underway on Tiritiri Matangi.
Ray’s legacy was felt throughout the day as stories of his dedication and passion for lighthouses and the Island were shared.
Ray Walter was born in Auckland in 1936 and grew up as an urban child living with the hardships of a mainly single-parent household during the Depression and the Second World War. He spent an extended period of his childhood in the Wilson Home for Crippled Children, suffering from a life-threatening illness.
Early on, he developed a fascination with lighthouses and, thanks to the influence of his seafaring stepfather, fell in love with the sea. He embarked on his own seafaring career in 1951, at the age of 15, working as a deck boy for the Union Steamship Company, on the Pacific, NZ coastal, and Australian trade routes.
Ray described himself as a romantic at heart, so it was hardly surprising that he first applied to join the lighthouse service when he was just 17 years old.
He was finally accepted into the service in August 1957, one month short of his 21st birthday. His first posting was to Puysegur Point in the southwest corner of the South Island, a very long way from urban Auckland.
Over his 27 years in the lighthouse service, Ray was stationed at Puysegur Point twice, Centre Island in Foveaux Strait, Cape Egmont in Taranaki, Farewell Spit at the northwest corner of the South Island, Portland Island off the Mahia Peninsula in Hawkes Bay, Castlepoint in the Wairarapa, and Mokohinau Island in the outer Hauraki Gulf. Finally, in 1980, he arrived at Tiritiri Matangi.
Ray was the last lighthouse keeper stationed at Tiritiri Matangi. When the lighthouse was automated in 1984, he embarked on a new career overseeing the ambitious ecological restoration that eventually transformed Tiritiri Matangi Island into New Zealand’s first open sanctuary, an international conservation success story.
Lighthouses remained an enduring passion for Ray, and the lighthouse museum on Tiritiri Matangi is an appropriate legacy.
Carl Hayson
Ray Walter up the lighthouse c1984
Lynda Walter
Lynda and Ray Walter on holiday on Tiritiri Matangi c1980
Photo: Paul Trevethick
Photo: Tiritiri archives
Tiritiri Matangi Kids,
by Stacey
Invertebrates are amazing because they have special superpowers that help nature run smoothly. They help plants grow, carry pollen between flowers, and keep everything in the environment working well. Read the superpowers and match them to the invertebrates.
1. This is the giant superhero of the insect world! With their mighty jaws, these leafcrunching champions can chomp through the toughest leaves. They’re nature’s ultimate cleanup crew, helping to keep the forest tidy and healthy.
3. This insect is a true marvel of nature, renowned for its remarkable ability to create mesmerising chromatic illusions. Its vibrant wings, with a striking combination of deep oranges, blacks, and whites, dance in the light, shifting in colour as they flutter. These dazzling patterns create illusions that can confuse predators and delight viewers.
5. This insect is nature's tiny tree designer! This clever critter spends years as a larva, becoming a master architect of its own secret hideout. Using its super skill, it carves out a snug burrow in a tree trunk and disguises the entrance with a silky web that looks just like bark. This clever camouflage keeps it safe from sneaky predators while it grows big and strong.
7. With its amazing superpower, this decomposer dynamo transforms old, rotting wood into brand-new energy to fuel the forest. It's like a tiny, unstoppable recycler, helping the forest stay fresh and healthy. This insect doesn't just munch—it’s a nutrient ninja, delivering food to plants and keeping the ecosystem sparkling clean.
2. These are the buzzing superheroes of the garden! With their fuzzy little bodies, they zip from flower to flower, carrying pollen. They help plants grow fruits and flowers, turning the world into a colourful buffet for everyone.
4. These insects are the ultimate team players, working together like a tiny army to build, solve problems, and carry things way bigger than themselves. With their secret signals and teamwork magic, they can take on challenges that would leave most creatures scratching their heads.
6. This creature is a master of versatility with its many legs that can move faster than a race car. Whether climbing, crawling, or building intricate designs, the animal adapts to any challenge with precision and power, making it the ultimate multi-tasker.
8. This little creature has a superpower that lets it stretch, bend, and twist its body in the most unbelievable ways.
Photo credits: Jonathan Mower, Neil Davies, Derek Tearne, Martin Sanders, John Sibley
Answers:- 1-H, 2-G, 3-E, 4-C, 5-F, 6-B, 7-A, 8- D.
A. Huhu Beetle: The Recycling Rockstar
B. Centipede: The Multi-Limb Marvel
C. Ant: The Collective Hive Mind
D. Looper Caterpillar: Elastic Evolution
E. Red Admiral Butterfly: Chromatic Illusions
F. Pūriri Moth: Bio Architect Mastery
G. Bees: The Pollen Party Pros
H. Wētāpunga: Mega Muncher
Supporters of Tiritiri Matangi
The Supporters of Tiritiri Matangi (SoTM) is a volunteer Incorporated Society that works closely with the Department of Conservation to make the most of the wonderful conservation-restoration project that is Tiritiri Matangi. Every year volunteers put thousands of hours into the project and raise funds through donations, guiding and our island-based gift shop.
If you'd like to share in this exciting project, membership is just $30 for a single adult or family; $35 if you are overseas; and $15 for children or students. Dawn Chorus, our magazine, is sent out to members every quarter. See www.tiritirimatangi.org.nz or contact PO Box 90-814 Victoria St West, Auckland.
SoTM Contacts:
Chairperson: Ian Alexander chairperson@tiritirimatangi.org.nz
Secretary: Val Lee secretary@tiritirimatangi.org.nz
Treasurer: Peter Lee-Grey treasurer@tiritirimatangi.org.nz
Board: Meredith Blogg, Hester Cooper, Rachel Goddard, Carl Hayson, Janet Petricevich, Mark Withers
Operations Manager: Debbie Marshall opsmanager@tiritirimatangi.org.nz
Guiding and Volunteer Manager: Gail Reichert guidemanager@tiritirimatangi.org.nz, 09 476 0010
Retail Manager: Ashlea Lawson retail@tiritirimatangi.org.nz
Membership: Rose Coveny membership@tiritirimatangi.org.nz
Educator: Sara Dean
Assistant Educator: Liz Maire educator@tiritirimatangi.org.nz
Fundraisers: Rashi Parker and Louise Delamare fundraiser@tiritirimatangi.org.nz
Social Media: Bethny Uptegrove socialmedia@tiritirimatangi.org.nz
Dawn Chorus co-editors: Janet Petricevich and Stacey Balich editor@tiritirimatangi.org.nz
Island Rangers: Talia Hochwimmer and Nick Fisentzidis tiritirimatangi@doc.govt.nz, 027 536 1067
CALENDAR OF EVENTS
Tiritiri Matangi Talks - Walking into the night: Experiencing Darkness and the Natural World
Monday 31st March 2025
Speaker Annette Lees
7:30pm at Unitec, Building 115, Mount Albert
Supporters' Social Evening
Monday 10th March
7:30pm at Fickling Centre, 546 Mount Albert Road, Three Kings.
Photography Tours
Saturday 29th March
Saturday 12th April
Saturday 26th April
Saturday 3rd May
Enquiries to the guiding and volunteer manager
Working Weekends 2025
Easter Weekend, 18th - 21st April
King's Birthday Weekend, 31st May - 2nd June
Labour Weekend, 25th - 27th October
Enquiries to the guiding and volunteer manager
Supporters' Weekends 2025
8th-9th March
5th-6th July
6th-7th September
4th-5th October
Enquiries to the guiding and volunteer manager
Tiritiri Matangi Talks - Save these dates
Monday 9th June 2025
Monday 1st December 2025
Visiting Tiritiri Matangi Island for education or recreation
Day trips:
Weather permitting, Explore runs a return ferry service from Wednesday to Sunday from Auckland Viaduct and the Gulf Harbour Marina. Bookings are essential.
Phone 0800 397 567 or visit the Explore website: www.exploregroup.co.nz/
Overnight visits:
Camping is not permitted and there is limited bunkhouse accommodation. Bookings are essential: https://bookings.doc.govt.nz/
School Education Programme
We offer a full-day learning experience in a pest-free environment for years 1 to 13. Tamariki and rangatahi can get up close to endangered taonga species where they learn about community conservation and how people can work together to provide protected habitat. This then inspires students to take action in their own neighbourhoods.
Our educators offer a range of education experiences on the Island, which are closely tied to the NZ curriculum. At the senior biology level, there is support material available for a number of NCEA achievement standards. Tertiary students have the opportunity to learn about the history of the Island and tools of conservation as well as to familiarise themselves with population genetics, evolution and speciation.
Subsidies are available for schools with an EQI 430 or more via our Growing Minds programme. Information on the education programme is at: https://www.tiritirimatangi.org.nz/education-programmes/ Bookings are essential.
Supporters of Tiritiri Matangi wishes to acknowledge the generous support of its sponsors
Supporters of Tiritiri Matangi welcomes all types of donations, including bequests, which are used to further our work on the Island. If you are considering making a bequest and would like to find out more, please contact secretary@tiritirimatangi.org.nz